/*
 * Copyright 2002-2017 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.integration.router;

import java.util.Collections;
import java.util.List;

import org.springframework.beans.factory.BeanFactoryAware;
import org.springframework.context.Lifecycle;
import org.springframework.core.convert.ConversionService;
import org.springframework.integration.handler.AbstractMessageProcessor;
import org.springframework.integration.handler.MessageProcessor;
import org.springframework.messaging.Message;
import org.springframework.util.Assert;

/**
 * A base class for Router implementations that delegate to a
 * {@link MessageProcessor} instance.
 *
 * @author Mark Fisher
 * @since 2.0
 */
class AbstractMessageProcessingRouter extends AbstractMappingMessageRouter
		implements Lifecycle {

	private final MessageProcessor<?> messageProcessor;


	AbstractMessageProcessingRouter(MessageProcessor<?> messageProcessor) {
		Assert.notNull(messageProcessor, "messageProcessor must not be null");
		this.messageProcessor = messageProcessor;
	}


	@Override
	public final void onInit() throws Exception {
		super.onInit();
		if (this.messageProcessor instanceof AbstractMessageProcessor) {
			ConversionService conversionService = getConversionService();
			if (conversionService != null) {
				((AbstractMessageProcessor<?>) this.messageProcessor).setConversionService(conversionService);
			}
		}
		if (this.messageProcessor instanceof BeanFactoryAware && this.getBeanFactory() != null) {
			((BeanFactoryAware) this.messageProcessor).setBeanFactory(this.getBeanFactory());
		}
	}

	@Override
	public void start() {
		if (this.messageProcessor instanceof Lifecycle) {
			((Lifecycle) this.messageProcessor).start();
		}
	}

	@Override
	public void stop() {
		if (this.messageProcessor instanceof Lifecycle) {
			((Lifecycle) this.messageProcessor).stop();
		}
	}

	@Override
	public boolean isRunning() {
		return !(this.messageProcessor instanceof Lifecycle) || ((Lifecycle) this.messageProcessor).isRunning();
	}

	@Override
	protected List<Object> getChannelKeys(Message<?> message) {
		Object result = this.messageProcessor.processMessage(message);
		return Collections.singletonList(result);
	}

}